A portative gas recognition system based on metal oxide gas sensor array [air pollution applications]

A portative electronic nose is conceived especially to detect several pollutant gases and estimate the concentration of these atmospheric components. The interest of our multisensor system is its entire autonomy, low weight and very small size for embedded applications, and its flexibility. Six commercial gas sensors (Figaro) with interesting cross sensitivity and almost low power consumption are used; a micro-controller equipped with a compact flash memory assures data acquisition, analyzing procedures, and data transfer or storage. The prototype is first validated in the laboratory by generating atmospheres containing various concentrations of three pollutant gases (H₂S, NO₂ and SO₂) in the range of industrial areas with variable humidity rate. An excellent group separation for the gas natures is obtained by using a multidimensional data analysis algorithm which also allows concentration determination of the gases.